Ferguson, Niall
Penguin Books, 2009
Buku Teks SO
National University of singapore, 2008
Majalah, Jurnal, Buletin
Fischer, Fritz
W.W. Norton, 1974
Buku Teks SO
edited by Alf Hornborg and Carole L. Crumley
Left Coast Press, 2007
Buku Teks
translated by Tam Lye Suan
Director-General Department of Infomartion Malaysia, 2008
Buku Referensi